Single-Particle Analysis of Metallic Nanoparticles Using Ultra-Fast Quadrupole based ICP-MS

Inductively coupled plasma mass spectrometry (ICP-MS) is considered a viable metrology tool for ENP quantitation and characterization due to its high specificity, sensitivity, and wide dynamic range. More recently, ICP-MS has been used in “single particle” mode to capture analyte signal pulses originating from individual nanoparticles in the ICP and relate the recorded data to information such as particle count, size distribution and analyte mass. For single-particle applications, quadrupole-based ICP-MS systems have been known to be limited by the dwell and settling time of the scanning electronics as well as the speed of the detection electronics. In addition, allowing shorter dwell times directly increases the upper limit of the dynamic range for nanoparticle analyses. In our laboratory, we have explored the possibility of a fast scanning mode with NexION 300 for dwell times as short as 1 μs, and with no settling time, for single mass determinations. The results show that the fast temporal behavior of the signal can be recorded in the pulse counting mode with sufficient number of data points to properly represent the pulse from a single nanoparticle. In this presentation, the latest results of our research work on the fast scanning mode for singleparticle ICP-MS will be discussed in detail.